Hello Ori Kabeli, welcome to the Microsoft community.
Based on your feedback, the voice speed of the edge reading function on your MAC is very fast.
Indeed, I also tested it and found the same issue.
This is because the engines developed for Apple computers and Windows systems are different, leading to this kind of difference.
Therefore, I am unable to provide you with a practical solution to this problem.
Please accept my sincere apologies for this.
If you have any suggestions for this feature, you can do so through:
Send feedback to Microsoft with the Feedback Hub app - Microsoft Support
Submit your thoughts and suggestions, the development team will regularly review the ideas or fixes submitted.
After submitting, please share the feedback link here, as this will allow other people on the forum to vote in support of your submission, including me. More votes will bring higher visibility and priority to the development team.
Hope the above information is helpful.
Kirito | Microsoft Community Support Specialist